摘要:Background and Aims: Body mass index (BMI) is known to be closely related to the prognosis and mortality of various diseases. The aim of our study was to evaluate differences in post-treatment overall survival (OS) according to BMI with hepatocellular carcinoma (HCC) and to understand the meaning of BMI. Among the records of 10,578 HCC patients registered at the Korean Central Cancer Registry from 2008 through 2014, we selected Barcelona Clinic Liver Cancer (BCLC) 0, A, and B staged HCC patients (n = 4,926). HCC patients showed a good prognosis in the order of overweight, normal weight, obesity, and underweight. However, comparing normal-weight (BMI 18.5–24.9 kg/m2) to overweight (BMI 25–29.9 kg/m2) after propensity score matching (PSM), there was no significant difference in OS (p = 0.153). Overweight males had a better prognosis than normal-weight males (p = 0.014), but, normal-weight females had a better prognosis than overweight. To determine the gender-specific OS differences, we examined the differences according to the HCC treatment type. In males, overweight patients had better OS after transarterial chemoembolization (TACE) (p = 0.039) than normal-weight, but not after surgical resection (p = 0.618) nor radiofrequency ablation (p = 0.553). However, in females, all of those HCC treatments resulted in significantly better OS in normal-weight patients than overweight. In patients with HCC of BCLC stages 0–B, unlike females, overweight males had a better prognosis than normal-weight, especially among TACE-treated patients. Our results carefully suggest that the meaning of normal BMI in patients with HCC may have gender difference.